According to landscape-america.com, sod is grass that has been grown from seed on a farm and then harvested by slicing off a thin layer of topsoil and then either rolling or stacking it. Therefore, sod is much easier to plant than lawn seed because it is a ready-made lawn. However, you still have to prepare the site for sod if you want the grass to grow optimally.
Clear all debris off the soil, and pull any weeds that are growing there. Rake up any large rocks.
Till the plot to loosen the soil until it is crumbly.
Spread a 4-to-6-inch layer of topsoil over the tilled soil.
Spread 1 lb. of 16-22-8 fertilizer over the soil.
Till the soil again to work the fertilizer into the soil to a depth of 3 inches.